Iowa City is the largest city in Johnson County, Iowa, United States, and its county seat. The population was 74,828 at the 2020 census, making it the state's fifth-most populous city. The Iowa City metropolitan area, which encompasses Johnson and Washington counties, has a population of over 171,000. The metro area is also a part of a combined statistical area with the Cedar Rapids metro area known as the Iowa City–Cedar Rapids region; collectively, this region has a population of nearly 500,000.